1. Technical Field
An aspect of the present invention relates to an auto-document feeder and an image forming apparatus, which may be installed in a multifunction device (MFD) having a plurality of functions, such as a scanning function, a printing function, and a copying function.
2. Related Art
Conventionally, an MFD having a main unit, in which mechanisms to form images are installed, and a reader unit, in which mechanisms to read images are installed, arranged on top of the main unit is known. Moreover, an MFD having, additionally to the main unit and the reader unit, a document conveyer unit with an auto-document feeder (ADF) arranged on top of the reader unit, is known.
The MFD in this configuration often has a rotatable structure, which enables the auto-document conveyer to rotate with respect to the reader unit. Therefore, when a user attempts to have the image read from the original document placed still on a platen glass, which is arranged in an upper part of the reader unit, in other words, when the user selects not to use the document conveyer unit, the user opens the document conveyer unit with respect to the reader unit to place the original document on the platen manually. On the other hand, when the user selects to use the document conveyer unit, the document conveyer unit is not moved but is maintained closed with respect to the reader unit while the image is being read. Moreover, the MFD may have another rotatable structure, which enables the reader unit to rotate with respect to the main unit. In this configuration, the document conveyer unit may be closed with respect to the reader unit, and the reader unit may be closed with respect to the main unit in an ordinary condition, e.g., during an image reading operation and when the MFD stands by for the image reading operation. Meanwhile, the reader unit may be opened to expose internal structures including the mechanisms to form the images when an operator provides maintaining works. Moreover, the MFD may be equipped with additional openable/closable structures.
With the plurality of openable/closable structures, it may be necessary to detect state of each openable/closable structure being open or closed. The open or closed state of each openable/closable structure may be detected by, for example, a switch or a sensor to sense opening/closing motions of the openable/closable structure may be provided to each openable/closable structure, and signals indicating ON and OFF output from the switch or the sensor may be detected.